Determinism concerns the relationship between cause and effect, between natural law and universal single specific phenomenon. In nature, given a cause or a law, it can occur only a certain effect or a particular phenomenon, and nothing else. So there is no space, in the Universe, for a spontaneous variation, nor for the pursuit of goals freely chosen.
If determinism is true we would not be free. If indeterminism is true, our actions would be random and our will would fail to control to be anyway morally responsible.
A key part of the debate "free will versus determinism" is the problem of ‘ causa prima’. Some believe that determinism and free will are mutually exclusive and that the consequence of determinism would be that free will is an illusion; others, however, called compatibilists, believe that the two ideas can coexist. Compatibilism (also known as soft determinism) admits that the existence of free will is well-suited with the fact that the universe is deterministic, while to the opposite, incompatibilism denies this possibility.
Much of the disputes stems from the fact that the definition of free will is not unique.
Some argue that it is referring to the metaphysical truth of acting independently, while others define it as the perception of being an actor that humans have when they act. For example, David Hume argued that it is possible that humans can form freely (regardless of context) their desires and beliefs, but the only "freedom" should be connected with the possibility of translating desires and beliefs into voluntary actions.
So, from a common point of view, free will would clash with determinism, namely the idea that all things that happen in the present and in the future are a necessary consequence caused by previous events. ‘Strong’ determinism which is a version of incompatibilism says that everything is determined, even actions and human wills. Libertarianism is consistent with the strong determinism only in rejecting compatibilism; but libertarians accept the existence of a free will together with the idea that there are some indeterminate things.
Now, at what extension the causal interpretation of reality holds? Each of us perceives himself as an individual, free - within certain limits - of self-determination. If all the world follows the laws of purely causality, assuming to know the rules that govern the time evolution of the world and the conditions at a given time we will be able to predict the future of the world ... including ourselves. This made someone think that our self-determination is in reality only apparent and illusory, contrary to what we seem to perceive.
The deterministic approach has undergone in the first half of the twentieth century a major blow with the loss of control of the column on which it was based, namely the principle of causality. This principle was in fact literally unbalanced as a result of a fundamental scientific discovery that took place in the twenties of the twentieth century in the field of quantum mechanics: the Heisenberg principle of indeterminacy. In fact, if one could imagine the universe as a system that is consequential, foreseeable, after the discovery of the uncertainty principle, epistemologically it cannot take it for granted, as you should be aware that the basic phenomena of reality can be described only in probabilistic terms.
A further and even more serious blow to determinism derived from the discovery of chaos theory in the second half of the twentieth century.
With the emergence of the ‘butterfly effect’, necessarily the classical determinism is having to be replaced by a conception in which the state of many phenomena in nature can only be expressed in probabilistic terms, keeping in many cases, but not always, a certain degree of regularity. This raises the concept of deterministic chaos, so it is still possible to maintain a certain degree of forecasting in physical models, but it becomes impossible to turn prediction into certainty.
The uncertainty principle of Heisenberg rises ‘wonderfully’ our self-determination: consider a system that contains a conscious subject. If we were able to predict the evolution of a deterministic system that the subject would not be self-determining, with an obvious absurdity. It is for this reason that studies on the awareness and the functioning of the mind connect the characteristics of the conscious subject to quantum indeterminacy.
For the Heisenberg indeterminacy it is not a special phenomenon of physical reality, but rather a universal and fundamental law of nature. As he writes, with the uncertainty principle and quantum mechanics "the non-validity of the law of causality is established definitively." Because "in the formulation of the law of causality clear if we know exactly the present-day, we can calculate the future" is false not the conclusion, but the premise. "We can not in principle know the present in every determining element
There is, in principle, no way to define unequivocally determinism or probabilism of physical phenomena.
Compatibilism – the belief that free will is compatible with a world where every action is determined by the events preceding it – has never been an easy sell.
See quotes below:
“... Nature almost surely operates by combining chance with necessity, randomness with determinism...”
― Eric Chaisson, Epic of Evolution: Seven Ages of the Cosmos
“If we are to make progress, we must not repeat history but make new history. We must add to inheritance left by our ancestors.”
― Mahatma Gandhi, The Wit and Wisdom of Gandhi
The question is interesting. I am surprised that there are few answers. Maybe it is set in too complex way that many people doubt that they can add something meaningful.
I will just try. There are several perspectives. The first is of nature without humans. Indeed, the laws of classical physics are deterministic. However, a room for randomness was opened by quantum mechanics.
Now let us take a point of individual human perspective. We can reflect on our actions and see in front of us a tree of open possibilities. So from our subjective perspective we have a free choice.
Next we have to go to the mechanism of our decision making (that we may even not fully recognize). Some people are driven by emotions and instincts: I want ice-cream just now no matter how much it costs. More rational people choose in restaurant's menu taking into account prices and their desires. Still in the end using economics we can come to a unique optimal decision. So it seems that we can predict actions of both rational people and emotional (if we would know why this emotion appears now). Is it a consequence of some chemical reaction in our brains?
A good example from literature is deductive activity of Sherlock Holmes and Dr. Watson who could derive all motives of criminals and influence of sudden events.
Dear Yuri,
your perspective is quite interesting! I accept your implicit suggestion to be more comprehensible. Thank you for your stimulating partecipation in the discussion.
Best regards, Gianrocco
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Physical Phenomena